Co-exchanged SSZ-13 zeolite membrane for boosting CO2/N2 separation

Zeolite membranes such as SSZ-13 combining the pore structures of 3.8 angstrom x 3.8 angstrom and membrane advantages of low energy consumption are promising for gas separation of CO2 from N2. However, the fabrication of high- quality SSZ-13 zeolite membranes with excellent CO2/N2 separation performance remains a challenge. In this work, a facile strategy of ion exchange is utilized in the fabrication of highly continuous crystallized Co-SSZ-13 membrane with modified pore chemistry. The Co-SSZ-13 membrane exhibits the optimal CO2 permeance of 6.6 x 10-8 mol s-1 m-2 Pa-1 and CO2/N2 separation factor (SF) of 27.7 which is 154 % and 80 % higher than NaSSZ-13 and Ca-SSZ-13 membranes, respectively. Moreover, such outstanding performance of the Co-SSZ-13 membrane is long-term stabilized for CO2/N2 separation. The introduction of Co(II) ions in the SSZ-13 structure can effectively reduce the pore size and provide the high electron density and d-orbitals which enhance both electrostatic and coordination interactions with CO2. This study provides guidance for the fabrication of advanced membranes with high-efficiency CO2 separation performance.